Add an accessibility alert for incorrect use of some accelerators.

ash/accelerators/accelerator_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/accelerators/accelerator_controller.h"
 
 #include <algorithm>
 #include <cmath>
 #include <iostream>
 #include <string>
@@ skipping 26 matching lines @@
 #include "ash/shell_window_ids.h"
 #include "ash/system/brightness_control_delegate.h"
 #include "ash/system/keyboard_brightness/keyboard_brightness_control_delegate.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/web_notification/web_notification_tray.h"
 #include "ash/touch/touch_hud_debug.h"
 #include "ash/volume_control_delegate.h"
+#include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/overview/window_selector_controller.h"
 #include "ash/wm/partial_screenshot_view.h"
 #include "ash/wm/power_button_controller.h"
 #include "ash/wm/window_cycle_controller.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/snap_sizer.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "content/public/browser/gpu_data_manager.h"
@@ skipping 372 matching lines @@
   for (size_t i = 0; i < kActionsAllowedAtLockScreenLength; ++i)
     actions_allowed_at_lock_screen_.insert(kActionsAllowedAtLockScreen[i]);
   for (size_t i = 0; i < kActionsAllowedAtModalWindowLength; ++i)
     actions_allowed_at_modal_window_.insert(kActionsAllowedAtModalWindow[i]);
   for (size_t i = 0; i < kReservedActionsLength; ++i)
     reserved_actions_.insert(kReservedActions[i]);
   for (size_t i = 0; i < kNonrepeatableActionsLength; ++i)
     nonrepeatable_actions_.insert(kNonrepeatableActions[i]);
   for (size_t i = 0; i < kActionsAllowedInAppModeLength; ++i)
     actions_allowed_in_app_mode_.insert(kActionsAllowedInAppMode[i]);
+  for (size_t i = 0; i < kActionsNeedingWindowLength; ++i)
+    actions_needing_window_.insert(kActionsNeedingWindow[i]);
 
   RegisterAccelerators(kAcceleratorData, kAcceleratorDataLength);
 
 #if !defined(NDEBUG)
   RegisterAccelerators(kDesktopAcceleratorData, kDesktopAcceleratorDataLength);
 #endif
 
   if (DebugShortcutsEnabled()) {
     RegisterAccelerators(kDebugAcceleratorData, kDebugAcceleratorDataLength);
     for (size_t i = 0; i < kReservedDebugActionsLength; ++i)
@@ skipping 68 matching lines @@
     // and will not be passed to the modal window. This is important
     // for things like Alt+Tab that would cause an undesired effect
     // in the modal window by cycling through its window elements.
     return true;
   }
   if (shell->delegate()->IsRunningInForcedAppMode() &&
       actions_allowed_in_app_mode_.find(action) ==
       actions_allowed_in_app_mode_.end()) {
     return false;
   }
+  if (MruWindowTracker::BuildWindowList(false).empty() &&
+      actions_needing_window_.find(action) != actions_needing_window_.end()) {
+    Shell::GetInstance()->accessibility_delegate()->TriggerAccessibilityAlert(
+        A11Y_ALERT_WINDOW_NEEDED);
+    return true;
+  }
 
   const ui::KeyboardCode key_code = accelerator.key_code();
   // PerformAction() is performed from gesture controllers and passes
   // empty Accelerator() instance as the second argument. Such events
   // should never be suspended.
   const bool gesture_event = key_code == ui::VKEY_UNKNOWN;
 
   // Ignore accelerators invoked as repeated (while holding a key for a long
   // time, if their handling is nonrepeatable.
   if (nonrepeatable_actions_.find(action) != nonrepeatable_actions_.end() &&
@@ skipping 459 matching lines @@
     keyboard_brightness_control_delegate) {
   keyboard_brightness_control_delegate_ =
       keyboard_brightness_control_delegate.Pass();
 }
 
 bool AcceleratorController::CanHandleAccelerators() const {
   return true;
 }
 
 }  // namespace ash